1. Field of the Invention
The invention relates to light-emitting diodes and more particularly to a location of an electrode of light-emitting diodes.
2. Description of the Related Art
A light-emitting diode (LED) is a semiconductor electronic component which can provide illumination. The light-emitting diode includes a p-doped semiconductor layer and an n-doped semiconductor layer. When the light-emitting diode is switched on, electrons are able to recombine with holes at the interface between the p-doped semiconductor layer and the n-doped semiconductor layer, releasing energy in the form of photons. This effect is called the electroluminescence of the light-emitting diode. Light-emitting diodes have many advantages over conventional incandescent light bulbs, including lower energy consumption, a longer lifespan, smaller size, high brightness, etc. Thus, light-emitting diodes are widely used in applications such as various electronic devices and general lighting.
Generally, a P-type electrode and an N-type electrode are respectively formed on the p-doped semiconductor layer and the n-doped semiconductor layer of the light-emitting diode. Moreover, in order to ensure the even distribution of current, the P-type electrode and the N-type electrode of the light-emitting diode further include a current expansion strip. In conventional light-emitting diodes, the current expansion strip of the P-type electrode is usually disposed on the p-doped semiconductor layer. The current expansion strip of the P-type electrode of conventional light-emitting diodes covers a part of a light-emitting area of the light-emitting diodes. The light-emitting area of the light-emitting diodes is thereby decreased and the luminous efficiency of the conventional light-emitting diodes is also reduced.